Add support for specifying host IP range with --ipbase.

bin/mn

@@ -192,6 +192,8 @@ class MininetRunner( object ):
                         help='|'.join( TESTS ) )
         opts.add_option( '--xterms', '-x', action='store_true',
                         default=False, help='spawn xterms for each node' )
+        opts.add_option( '--ipbase', '-i', type='string', default='10.0.0.0/8',
+                         help='base IP address for hosts' )
         opts.add_option( '--mac', action='store_true',
                         default=False, help='automatically set host MACs' )
         opts.add_option( '--arp', action='store_true',
@@ -248,6 +250,7 @@ class MininetRunner( object ):
             self.validate( self.options )
 
         inNamespace = self.options.innamespace
+        ipBase = self.options.ipbase
         xterms = self.options.xterms
         mac = self.options.mac
         arp = self.options.arp
@@ -257,6 +260,7 @@ class MininetRunner( object ):
         mn = Mininet( topo=topo, 
                       switch=switch, host=host, controller=controller, 
                       intf=intf,
+                      ipBase=ipBase,
                       inNamespace=inNamespace,
                       xterms=xterms, autoSetMacs=mac,
                       autoStaticArp=arp, listenPort=listenPort )

mininet/net.py

@@ -97,7 +97,7 @@ from mininet.log import info, error, debug, output
 from mininet.node import Host, OVSKernelSwitch, Controller
 from mininet.link import Link
 from mininet.util import quietRun, fixLimits
-from mininet.util import macColonHex, ipStr, ipParse
+from mininet.util import macColonHex, ipStr, ipParse, netParse
 from mininet.term import cleanUpScreens, makeTerms
 
 class Mininet( object ):
@@ -105,7 +105,7 @@ class Mininet( object ):
 
     def __init__( self, topo=None, switch=OVSKernelSwitch, host=Host,
                  controller=Controller, link=Link, intf=None, 
-                 build=True, xterms=False, cleanup=False,
+                 build=True, xterms=False, cleanup=False, ipBase='10.0.0.0/8',
                  inNamespace=False,
                  autoSetMacs=False, autoStaticArp=False, listenPort=None ):
         """Create Mininet object.
@@ -130,6 +130,7 @@ class Mininet( object ):
         self.controller = controller
         self.link = link
         self.intf = intf
+        self.ipBase = ipBase
         self.inNamespace = inNamespace
         self.xterms = xterms
         self.cleanup = cleanup
@@ -214,6 +215,8 @@ class Mininet( object ):
            At the end of this function, everything should be connected
            and up."""
 
+        ipBaseNum, prefixLen = netParse( self.ipBase )
+
         if not topo:
             topo = self.topo()
 
@@ -222,7 +225,9 @@ class Mininet( object ):
             name = prefix + topo.name( nodeId )
             ni = topo.nodeInfo( nodeId )
             # Default IP and MAC addresses
-            defaults = { 'ip': topo.ip( nodeId ) }
+            defaults = { 'ip': topo.ip( nodeId,
+                                        ipBaseNum=ipBaseNum,
+                                        prefixLen=prefixLen ) }
             if self.autoSetMacs:
                 defaults[ 'mac'] = macColonHex( nodeId ) 
             defaults.update( ni.params )

mininet/topo.py

@@ -16,6 +16,7 @@ setup for testing, and can even be emulated with the Mininet package.
 # from networkx.classes.graph import Graph
 
 from networkx import Graph
+from util import netParse, ipStr
 
 class NodeID(object):
     '''Topo node identifier.'''
@@ -42,15 +43,22 @@ class NodeID(object):
         '''
         return str(self.dpid)
 
-    def ip_str(self):
+    def ip_str(self, ipBase=None, prefixLen=8, ipBaseNum=0x0a000000):
         '''Name conversion.
-
+        ipBase: optional base IP address string
+        prefixLen: optional IP prefix length
+        ipBaseNum: option base IP address as int
         @return ip ip as string
         '''
-        hi = (self.dpid & 0xff0000) >> 16
+        if ipBase:
-        mid = (self.dpid & 0xff00) >> 8
+            ipnum, prefixLen = netParse( ipBase )
-        lo = self.dpid & 0xff
+        else:
-        return "10.%i.%i.%i" % (hi, mid, lo)
+            ipBaseNum = ipBaseNum
+        # Ugly but functional
+        assert self.dpid < ( 1 << ( 32 - prefixLen ) )
+        mask = 0xffffffff ^ ( ( 1 << prefixLen ) - 1 )
+        ipnum = self.dpid + ( ipBaseNum & mask )
+        return ipStr( ipnum )
 
 
 class Node( object ):
@@ -113,7 +121,8 @@ class Topo(object):
         """Create Topo object.
            node: default node/host class (optional)
            switch: default switch class (optional)
-           link: default link class (optional)"""
+           link: default link class (optional)
+           ipBase: default IP address base (optional)"""
         self.g = Graph()
         self.node_info = {}  # dpids hash to Node objects
         self.edge_info = {}  # (src_dpid, dst_dpid) tuples hash to Edge objects
@@ -342,13 +351,13 @@ class Topo(object):
         '''
         return self.id_gen(dpid = dpid).name_str()
 
-    def ip(self, dpid):
+    def ip(self, dpid, **params):
         '''Get IP dotted-decimal string of node ID.
-
         @param dpid DPID of host or switch
+        @param params: params to pass to ip_str
         @return ip_str
         '''
-        return self.id_gen(dpid = dpid).ip_str()
+        return self.id_gen(dpid = dpid).ip_str(**params)
 
     def nodeInfo( self, dpid ):
         "Return metadata for node"

mininet/util.py

@@ -204,14 +204,14 @@ def macColonHex( mac ):
        returns: macStr MAC colon-hex string"""
     return _colonHex( mac, 6 )
 
-def ipStr( ip ):
+def ipStr( ip, defaultNet=10 ):
     """Generate IP address string from an unsigned int.
        ip: unsigned int of form w << 24 | x << 16 | y << 8 | z
        returns: ip address string w.x.y.z, or 10.x.y.z if w==0"""
-    w = ( ip & 0xff000000 ) >> 24
+    w = ( ip >> 24 ) & 0xff
     w = 10 if w == 0 else w
-    x = ( ip & 0xff0000 ) >> 16
+    x = ( ip  >> 16 ) & 0xff
-    y = ( ip & 0xff00 ) >> 8
+    y = ( ip  >> 8 ) & 0xff
     z = ip & 0xff
     return "%i.%i.%i.%i" % ( w, x, y, z )
 
@@ -225,6 +225,15 @@ def ipParse( ip ):
     args = [ int( arg ) for arg in ip.split( '.' ) ]
     return ipNum( *args )
 
+def netParse( ipstr ):
+    """Parse an IP network specification, returning
+       address and prefix len as unsigned ints"""
+    prefixLen = 0
+    if '/' in ipstr:
+        ip, pf = ipstr.split( '/' )
+        prefixLen = int( pf )
+    return ipParse( ip ), prefixLen
+
 def checkInt( s ):
     "Check if input string is an int"
     try: